Field
Various features relate to a substrate that includes stacks of interconnects, an interconnect on a solder resist layer and an interconnect on a side portion of the substrate.
Background
FIG. 1 illustrates a die 100 mounted on a substrate 102. The substrate 102 is mounted on a printed circuit board (PCB) 106 through a set of solder balls 104. The substrate 102 may include several traces, pads and vias (which are not shown). These traces, pads, and vias are used to provide electrical paths to and from the die 100. The set of solder balls 104 are configured to provide electrical paths for a ground reference signal, power signals and input/output signals. However, current integrated circuit designs of the substrate 102 require that the number of solder balls (from the set of solder balls 260) used for a ground reference signal be about the same as the number of solder balls (from the set of solder balls 260) used for power signals and input/output signals. Typically, a signal solder ball configured to provide an electrical path for a power signal or input/output signal is required to be located next to a ground solder ball that is configured to provide an electrical path for a ground reference signal. For example, as shown in FIGS. 1 and 2, the solder balls 140 are arranged in an alternative matter to provide an electrical path for a ground reference signal (G) and a non-ground reference signal (S). This requirement results in solder balls taking up a lot real estate in an integrated device package and/or the substrate 102. As shown in FIG. 2, the solder balls configured to provide an electrical path for a ground reference signal (G) make up a majority of the solder balls. Solder balls that are used for providing an electrical path for a ground reference signal (G) is an opportunity cost, since that solder balls cannot be used to provide a non-ground reference signal.
There is a constant need to reduce the size and/or form factors of an integrated device package. Often times, the size of the solder balls limit how small an integrated device package can be, since solder balls are large relative to other interconnects in the substrate. This in turns, limits how closely and densely interconnects can be formed in an integrated device package and/or package substrate.
Therefore, there is a need for an improved integrated device package and/or package substrate. Ideally, such an integrated device package and/or package substrate will have a better solder ball design that will allow for a smaller form factor for the integrated device package and/or the package substrate while also having better performance, without having to sacrifice the structural stability of the device.